/Engine/Plugins/Runtime/RigVM/Source/RigVMDeveloper/Public/EdGraph/RigVMEdGraphSchema.h
Sets the string to the specified pin; even if it is invalid it is still set.
virtual void TrySetDefaultValue ( [UEdGraphPin](API\Runtime\Engine\EdGraph\UEdGraphPin) & Pin, const [FString](API\Runtime\Core\Containers\FString) & NewDefaultValue, bool bMarkAsModified ) const